Which branch circuit setup is permissible when multiple voltages are involved?

Identifying by nominal voltage system as the permissible setup for branch circuits involving multiple voltages is based on the principle of safety and compliance with the National Electrical Code (NEC). Proper identification of circuits by their nominal voltage ensures that all electrical work adheres to regulations that promote safe operation and reduce the risk of accidents.

When circuits operate at different voltage levels, they can pose risks if not clearly identified, potentially leading to dangerous mismatches or incorrect connections. By maintaining clear identification of their nominal voltage, electricians and users can establish a clear understanding of each circuit's purpose and capabilities. This identification helps ensure that all system components are appropriately rated for their respective voltages, mitigating the risk of equipment failure or hazardous conditions.

This approach aligns with NEC guidelines, which advocate for proper labeling and identification in electrical systems. It fosters awareness and helps avoid dangerous scenarios that may arise from inadvertent mixing of components meant for different voltage levels.